Method of bioconversion of industrial or agricultural cellulose containing wastes

ABSTRACT

A method of bioconversion of organic industrial or agricultural cellulose containing wastes into proteinaceous product. The method comprises comminution of the wastes with moistening and addition of a starting culture inducing their biological degradation and conversion into simple carbohydrates. The carbohydrates are fermented into digestible products. The starting culture comprises cleaving enzymes produced by edible microorganisms such as fungus and bacteria selected from the group consisting of Ilumicola grisea, Trichoderma harzanum, Ruminococcus albus.

FIELD OF INVENTION

The present invention relates to utilization of organic wastescontaining cellulose and occurring as surplus and waste residuesassociated both with agricultural and industrial manufacture.

More particularly, the present invention refers to the transferring oforganic waste materials into animal feed product by virtue of thebio-conversion of a cellulosic component of such wastes into simplecarbohydrates with subsequent fermenting thereof into digestibleproducts. As an example of such wastes one can mention the straws ofcereal grains such as wheat, barley, rice, oats, etc., corn stover,sugarcane bagasse, cotton, wood sawdust, paper pulp and pulp millsludges.

It should be understood, however, that the present invention is notlimited to the above listed wastes, but the scope thereof includes theutilization of other organic wastes containing a cellulose component.

BACKGROUND OF THE INVENTION

At present, it is commonly acceptable to utilize various cheap organicrow materials present in the wastes of agricultural or industrialmanufactures for the production of animal feed products. Therefore,available agricultural and industrial wastes represent a valuableresource for microbiological synthesis of such feed; their fermentationis of considrable practical importance. One should also bear in mindthat manufacturing food products per se from organic wastes is only oneaspect of their utilization while another and not less important one isthe environmental aspect, since the utilization of wastes is associatedwith cleaning of the environment therefrom.

There is a known-in-the-art method for producing proteinaceous animalfodder from organic vegetable wastes by bio-degradation thereof withsubsequent fermentation.

In U.S. Pat. No. 5,198,252, Simsa et al. discloses a method for themanufacture of fodder and/or soil improving agents by anaerobic oraerobic fermentation of vegetable environmental wastes such as aquaticplants, specifically the water hyacinth (Eichhornia crassipes).

The known method comprises the comminuting of harvested plants, mixingthem with the organic waste material of the food industry and/oragriculture industry, adding to the mixture an inoculating agent, abiological degradation agent and a starter culture and, finally,anaerobically fermenting the mixture for 2-45 days.

An inoculating agent is selected from the group including a pectincleaving enzyme and a thermophillic lactic acid bacterial culture. Adegradation agent is chosen from the group consisting of molasses, ureaand organic carboxylic acids, and a starter culture having highcellulase activity is selected from the group consisting of Trichodermaviridae, Chaetonium globusum and Actinomycetes.

There are a number of serious disadvantages associated with the methoddisclosed in the above patent. The first of these disadvantages lies inthe fact that the known method requires mixing of the comminuted wasteswith a ready-to-use commercially available enzyme, namely pectinaze,which is a relatively expensive product and has reduced cleavingefficiency compared with the efficiency of an enzyme which could beformed in situ by a microorganism during the bio-conversion processitself.

Another significant shortcoming of the known method is the introductionof molasses, which is a source of glucose and pentozes. It is well knownthat these carbohydrates inhibit the hydrolysis process effected by astarter culture and thus reduce the efficiency of the wholebio-conversion process. As a result the cellulose initially contained inaquatic plants and vegetable wastes may remain unconverted within thefodder. Furthermore, the above carbohydrates inhibit the fermentation ofthe starter culture pectinaze, thus preventing the hydrolysis of pectineinitially contained in wastes. Pectin may also remain unconverted in thefodder. All of the above are associated with receiving a food productwhich has a high content of cellulose and low digestibility.

Unfortunately, the introduction of molasses is associated with even moredisadvantages, namely, with the fact that the formation of organic acidsduring biological degradation and fermentation of the mixture takesplace because of the hydrolysis of cellulosic products contained in thewaste itself, i.e. cellulose, hemicellulose, lignin, and not because ofthe fermentation and assimilation of carbohydrates contained inmolasses. This also reduces the efficiency of the bio-conversion processand thus the quality of the final product.

OBJECTS OF THE INVENTION

The object of the present invention is to provide for a new and improvedmethod of utilizing the organic agricultural or industrialcellulose-containing wastes which would sufficiently reduce or overcomethe above mentioned drawbacks of the known method.

In particular, the main object of the present invention is to providefor a new and improved method of utilizing organic cellulose containingwastes, which enables production of a proteinaceous nutrition productwhich has an increased amount of protein and improved digestibility.

The second object of the present invention is to provide for a new andimproved method of utilizing of organic wastes without the use ofmolasses or any other substances containing glucose or othercarbohydrates.

A further object of the present invention is to provide for a new andimproved method for the bio-conversion of organic wastes into ediblefood products suitable for the nutrition of microorganisms by utilizingorganic wastes, for example, animal or poultry manure.

The above and other objects of the present invention are achieved byvirtue of dedicated microorganisms capable of effecting the hydrolysisof cellulosic products up to glucose, cellobiose and pentose withsubsequent assimilation thereof by said microorganisms and conversioninto organic acids and protein.

The above and other objects and advantages of the present invention canbe achieved in accordance with the following combination of itsessential features, referring to different embodiments thereof. Theseembodiments can be attributed to three independent groups, one of whichrefers to a method of bio-conversion of organic cellulose containingwastes into a nutrition product, another one into a nutrition productproduced by the bio-conversion method and the third one to a startingculture necessary for effecting the bio-conversion method.

The first group of embodiments of the present invention refers to amethod of utilization of organic wastes.

According to one of the preferred embodiments the method comprises thefollowing steps:

a) the comminution of organic wastes into particulated form

b) the moistening of said wastes up to at least 45%

c) the addition to said wastes of a starting culture, said startingculture comprising a source of cleaving enzymes capable of inducingbiological degradation of a cellulosic material present within saidwastes and the conversion thereof into simple carbohydrates,

d) the fermenting of said simple carbohydrates into digestible products.

In accordance with another embodiment the source of cleaving enzymecomprises an edible microorganism, said microorganism being a fungus orbacteria chosen from the group including Humicola grisea, Trichodermaharzianum, Ruminococcus Albus or mixtures thereof.

As per still a further preferred embodiment the method comprises theaddition to said wastes of a fermenting microorganism, preferablymesofilic lactic acid bacteria cultures chosen from the group containingLactococcus lactis susp.cremoris, Lactococcus lactis susp. or mixturesthereof.

In accordance with another preferred embodiment the method comprises theaddition to said wastes of a yeast capable of genrating protein withinthe edible microorganism, e.g., Sacharomyces cerevisiae.

According to still a further preferred embodiment the method comprisesthe addition to said wastes of at least one substance suitable for thenutrition of said starting culture.

In another preferred embodiment this substance is an organic orinorganic substance chosen from the group consisting of (NH₄)₂ SO₄,urea, NaCl, animal or poultry manure or a combination thereof.

In yet another preferred embodiment the method comprises the packing ofmoistened wastes together with said starting culture into a vacuum-tightpackage so as to conduct the fermenting step substantially under theexclusion of air.

In accordance with still a further preferred embodiment said fermentingstep is conducted for 1-10 days, preferably for 5-10 days.

The second group of preferred embodiments of the present inventionrefers to a proteinaceous nutrition product per se and in accordancewith one of the preferred embodiments this product comprises:

a) a cellulosic component containing in organic wastes and which issuitable for cleaving into simple carbohydrates, said cellulosiccomponent being comminuted into particulated form, and

b) a starting culture capable of inducing biological degradation of saidcomminuted cellulosic component and cleaving thereof into simplecarbohydrates with subsequent fermenting thereof into digestibleproducts.

In another preferred embodiment said starting culture comprises a sourceof cleaving enzyme, said source being an edible microorganism,preferably a fungus or bacteria chosen from the group including Humicolagrisea, Trichoderma harzianum, Ruminoccocus albus or mixtures thereof.

As per still a further embodiment said starting culture comprises adedicated fermenting means capable of inducing fermentation of saidsimple carbohydrates into organic acids, vitamins or other digestibleproducts.

According to another embodiment said fermenting means is a mesofiliclactic acid bacteria culture chosen from the group containingLactococcus lactis susp.cremoris, Lactococcus lactis subsp. Lactis ormixtures thereof.

In a further embodiment said starting culture comprises a yeast capableof synthesizing protein within the edible microorganism, e.g.Sacharomyces cerevisiae.

In still a further embodiment the product comprises at least oneadditive suitable for nutrition of said starting culture, said additivebeing an organic or inorganic substance chosen from the group consistingof (NH₄)₂ SO₄, urea, NaCl, animal or poultry manure or combinationsthereof.

According to another preferred embodiment the product comprises at least45% of moisture, and it is placed within a vacuum-tight package.

The third group of embodiments refers to a starting culture per se andin accordance with one of the preferred embodiments this culturecomprises a source of cleaving enzymes capable of inducing thebiological degradation of cellulosic material contained in organicwastes and cleaving thereof into simple carbohydrates with subsequentfermenting thereof into digestible products.

As per another the source the cleaving enzyme is an ediblemicroorganism, preferably a fungus or bacteria chosen from the groupincluding Humicola grisea, Trichoderma harzianum, Ruminoccocus albus ormixtures thereof.

In a further embodiment the starting culture comprises a dedicatedfermenting means capable to inducing the fermentation of simplecarbohydrates into organic acids, vitamins or other digestible products.

According to still a further embodiment, said fermenting means is amesofilic lactic acid bacteria culture chosen from the group containingLactococcus lactis susp.cremoris, Lactococcus lactis subsp. lactis ormixtures thereof.

As per yet another embodiment the starting culture comprises a yeastcapable of generating protein within said edible microorganism, e.g.,Sacharomyces cerevisiae.

The present invention in its various embodiments referring to thedifferent groups above has only been briefly summarized.

For a better understanding of the present invention as well of itsbenefits and advantages, reference will now be made to the followingdescription of its embodiments taken in combination with theaccompanying drawing.

BRIEF DESCRIPTION OF THE DRAWING

FIG. 1 schematically shows a flow chart diagram of a method for theutilization of organic wastes in accordance with the present inventionand a system for implementation of said method.

DETAILED DESCRIPTION OF SPECIFIC EMBODIMENTS

With reference to FIG. 1, schematically presented there is a flow chartfor implementation of the present invention by virtue of a systemcomprising the following main units: a tank 1 with water solution ofmineral salts for moisturizing of organic wastes, a fermenter 2 withaqueous solution suitable for the cultivation of microorganisms requiredfor effecting the bio-conversion of organic wastes, a preparation unit 3for receiving the row wastes, comminuting and moisturizing thereof,mixing with the starting culture and with other components andhomogenizing, a packaging unit 4 for placing the mixture intoappropriate plastic containers, a sealing unit 5 for vacuum tightsealing of containers and a storage/fermentation unit 6 for storingsealed containers and fermentation of the biomass packed therein.

The utilization of organic wastes containing cellulose and the transferthereof into a nutrition product suitable for animal feed is carried outin accordance with the present invention as follows. Vegetable wastes,for example, wheat straw are brought to preparation unit 1 and areground up therein to particles size 1.0-1.5 cm. Then the liquid solutionof the starting culture from fermenter 2 and aqueous solution of mineralsalts from tank 1 are added to the contents of the preparation unit.Upon moistening of wastes up to 60-65% the mixture is homogenized withinthe preparation unit and is forwarded therefrom to packaging unit 4 forplacing into polyethylene bags and then to sealing unit 5 for vacuumtight sealing. From this point the sealed bags are transported to astorage/fermentation unit where appropriate humidity and temperature18-30° C. are kept so as to effect fermentation of the mass withinsealed bags under the exclusion of air for 1-10 days up to the obtainingof a proteinaceous nutrition product. The final product can be stored insealed bags for 1 year.

In the diagram the preparation unit is shown as a single unit, in whichcomminuting, moisturizing, mixing with starting culture and homogenizingof the mixture are carried out. It should be realized, however, that inpractice it is not necessary that all the above steps take place in thesame unit. For example, comminuting of wastes can be done in a separatepiece of equipment from which the ground waste is transported to a binof preparation unit. Here the ground wastes are moisturized and mixedwith the starting culture to initiate the bio-conversion.

In accordance with the present invention it has been empirically foundthat excellent properties of the final nutrition product in terms ofamount of protein and digestibility can be achieved if the startingculture comprises at least one edible microorganism which is a fungus orbacteria chosen from the group including Humicola griseas, Trichodermaharzianum, Ruminococcus albus or combinations thereof. It is alsoadvantageous if the bio-synthesis of protein in the ediblemicroorganisms is promoted, for example, by means of a yeast which isadded to the starting culture. As such a yeast one can use, for example,Sacharomyces cerevisiae which has an activity of 10¹⁰ cells per gram ofdry substance.

It has also been empirically established that the efficency ofbio-conversion, in general, and fermentation, in particular, can besignificantly improved if a fermenting microorganism is added to saidwastes, said microorganism being a mesofilic lactic acid bacteriaculture chosen from the group containing Lactococcus lactissusp.cremoris, Lactococcus lactis subsp. or mixtures thereof.

It is also beneficial for the quality of the final product if at leastone substance suitable for nutrition of microorganisms of the startingculture is added to the unconverted wastes before bringing therein thestarting culture. Examples of such substances are organic or inorganicsalts, urea, animal or poultry manure. It might be advantageous if thesesubstances are prepared as an aquaeous solution within tank 1 and areadded therefrom to the unconverted wastes brought to preparation unit 1.It should be realized, however, that these substances can be added tothe unconverted wastes in dry form with subsequent moisturizing.

With reference to the following non limited examples 1-4 the presentinvention will now be disclosed in more details.

EXAMPLE 1

1000 kg of wheat straw wastes are ground up to a particle size 1-1.5 cmwithin a bin of the fermenter 2. To the ground wastes are added 12 kg of(NH₄)₂ SO₄, 8 kg of urea and 5 kg of NaCl. The mixture is moisturized bywater up to 60-65% of the weight of dry straw wastes and then a startingculture is introduced, said culture consisting of 0.5 g of Sacharomycescerevisiae, 0.5 g of a mixture of dry mesofilic lactic acid bacteriacultures Lactococcus lactis susp.cremoris, Lactococcus lactis subsp.lactis, 0.5 g of Humicola grisea, 0.5 g of Trichoderma harzianum and 0.5g of Ruminococcus albus. The mixture is mixed, homogenized, packed inpolyethylene bags and vacuum-tight sealed. The fermentation processtakes place in sealed bags during 1-10 days at 25-30 ° C. Fermentationresulted in a nutrition ruminant product, the composition of whichincluded protein, organic acids and group B vitamins.

Summarized in non limiting table 1 below is the content of the nutritionproduct produced in accordance with the above procedure compared withthe content of a non converted dry straw.

From the results it follows that the bio-converted nutrition productcontains 15% protein, 1-7% lactic acid, and 0.5-1.0% acetic acid. Theamount of cellulose after fermentation, in comparison, with dry straw isreduced by 10%, lignin by 5.7% and non destructible fiber (NDF) by 24%.

                  TABLE 1                                                         ______________________________________                                        Compound        Unit     Dry straw Example 1                                  ______________________________________                                        Fat             g/100 g  0.0       1.0                                        Crude protein   g/100 g  3.0       15.0                                       Ashes                    10.4      15.0                                       Cellulose                48.8      38.8                                       Lignin                   30.0      24.6                                       Lactic acid              0.0       7.0                                        Acetic acid              0.0       1.0                                        pH                       6.0       4.2                                        NDF (non destructible fiber)                                                                           54.0      30.0                                       ______________________________________                                    

EXAMPLE 2

500 kg of wheat straw wastes are ground up using the the procedure andequipment similar to that of example 1. Added to the ground wastes are500 kg of poultry manure, 12 kg of (NH₄)₂ SO₄, 5 kg of NaCl and themixture is moisturized by water up to 60-65% of the weight of the drystraw. Added to the moist mixture is a starting culture consisting of1.5 g of a mixture of mesofilic lactic acid bacteria culturesLactococcus lactis susp.cremoris, Lactococcus lactis subsp. lactishaving an activity of 10¹⁰ cells per gram of dry substance, 0.5 g ofHumicola grisea, 0.5 g of Trichoderma harzianum and 0.5 g ofRuminococcus albus. The mixture is thoroughly mixed, homogenized, packedin sealed vacuum-tight polyethylene bags. The fermentation process takesplace in sealed bags during 1-10 days at 25-30C. Fermentation results ina nutrition product, the composition of which includes protein, organicacids, fat and group B vitamins.

Summarized in non limiting table 2 below is the content of the nutritionproduct produced in accordance with the above procedure compared withthe content of a non converted dry straw.

                  TABLE 2                                                         ______________________________________                                        Compound        Unit     Dry straw Example 2                                  ______________________________________                                        Fat             g/100 g  1.31      4.45                                       Crude protein   g/100 g  7.34      20.79                                      Ashes                    18.82     27.61                                      Cellulose                27.70     17.50                                      Lignin                   10.80     5.00                                       Lactic acid              0.00      6.30                                       Acetic acid              0.00      2.70                                       pH                       7.50      4.75                                       NDF (non destructible fiber)                                                                           56.10     37.87                                      ______________________________________                                         From the above results it follows that the bioconverted nutrition product     contains 10-20% protein, 1-7% lactic acid, 0.5-1.0% acetic acid, 4.0-4.5%     fat. The amount of cellulose after fermentation, in comparison with           unconverted dry straw, is reduced by 10.2%, lignin by 5.8% and non            destructible fiber (NDF) by 18.23%.                                      

EXAMPLE 3

850 kg of algae seaweed wastes of agar--agar manufacture together with150 kg of wheat straw are ground up using a procedure and equipmentsimilar to that of example 1. Added to the ground up wastes there are 12kg of (NH₄)₂ SO₄. The mixture is moisturized by water up to 60-65% ofthe weight of dry wastes. Added to the moist mixture is a startingculture consisting of 1.5 g of a mixture of mesofilic lactic acidbacteria cultures Lactococcus lactis susp.cremoris, Lactococcus lactissubsp. lactis, 0.5 g of Humicola grisea, 05 g of Trichoderma harzianumand 0.5 g of Ruminococcus albus. The mixture is thoroughly mixed,homogenized, packed in sealed vacuum-tight polyethylene bags. Thefermentation process takes place in sealed bags during 1-10 days at25-30° C. Fermentation results in a nutrition product the composition ofwhich includes protein and organic acids.

Summarized in non limiting table 3 is the content of nutrition productproduced in accordance with the above procedure compared with thecontent of a non converted algae straw.

                  TABLE 3                                                         ______________________________________                                        Compound        Unit     Algae straw                                                                             Example 3                                  ______________________________________                                        Fat             g/100 g  1.31      1.60                                       Crude protein   g/100 g  11.00     25.80                                      Ashes                    8.00      9.15                                       Lactic acid              0.00      12.00                                      Acetic acid              0.00      1.00                                       pH                       7.00      4.20                                       NDF (non destructible fiber)                                                                           28.50     20.0                                       ______________________________________                                         From the above results it follows that bioconverted nutrition product         contains 25.8% protein, 12% lactic acid, 1.0% acetic acid. The amount of      non destructible fiber (NDF) is reduced by 8.5%.                         

EXAMPLE 4

500 kg of cotton straw and cotton seed wastes are ground up to aparticle size of 0.5 cm in equipment similar to that of example 1. Addedto the ground wastes are 500 kg of sterile poultry manure, 12 kg of(NH₄)₂ SO₄, 5 kg of NaCl and the mixture is moisturized so as to bringthe moisture content up to 60-65% of the weight of dry wastes. Added tothe moist mixture is a starting culture consisting of 1.5 g of a mixtureof mesofilic lactic acid bacteria cultures Lactococcus lactissusp.cremoris, Lactococcus lactis subsp. lactis, 0.5 g of Humicolagrisea, 0.5 g of Trichoderma harzianum and 0.5 g of Ruminococcus albus.The mixture is thoroughly mixed, homogenized, packed in polyethylenebags and vacuum-tight sealed. The fermentation process takes place insealed bags during 1-12 days at 18-30° C. Fermentation results in anutrition product the composition of which includes protein, organicacids and group B vitamins.

In non limiting table 4 below there is summarized content of nutritionproduct produced in accordance with the above procedure compared withthe content of non converted dry cotton wastes.

                  TABLE 4                                                         ______________________________________                                        Compound        Unit    Cotton wastes                                                                             Example 4                                 ______________________________________                                        Fat             g/100 g 0.5         1.5                                       Crude protein   g/100 g 7.0         14.3                                      Ashes                   20.0        22.0                                      Cellulose               33.0        25.0                                      Lignin                  28.9        23.2                                      Lactic acid             0.0         7.0                                       Acetic acid             0.0         0.5                                       pH                      4.2         4.2                                       NDF (non destructible fiber)                                                                          54.5        42.5                                      ______________________________________                                         From the above results it follows that the bioconverted nutrition product     contains 10-14% protein, 1-7% lactic acid, 0.5-1.0% acetic acid. The          amount of cellulose after fermentation in comparison with dry unconverted     cotton wastes is reduced by 8%, lignin by 5.7% and non destructible fiber     (NDF) by 12%.                                                            

It should be appreciated that the present invention is not limited tothe above-described examples and embodiments and that changes andmodifications can be made by one ordinarily skilled in the art withoutdeviation from the scope of the invention as will be defined below inthe appended claims.

It should also be appreciated that the features disclosed in theforegoing description, and/or in the following claims, and/or in theaccompanying drawings, and/or examples, and/or tables may, bothseparately and in any combination thereof, be material for realizing thepresent invention in diverse forms thereof.

What is claimed is:
 1. A process of conversion of low protein, cellulosecontaining waste into a fodder or fodder supplement, the processcomprising the steps of:(a) inoculating the waste under aerobicconditions with a first inoculum including at least one firstmicroorganism capable of converting cellulose into carbohydrates and atleast one second microorganism capable of converting carbohydrates intoproteins to thereby efficiently convert at least a portion of saidcellulose into nutritional proteins and prevent accumulation of saidcarbohydrates and thereby inhibition of said conversion of saidcellulose into said carbohydrates; and (b) inoculating the waste, underanaerobic conditions, with a second inoculum including at least onethird microorganism capable of converting cellulose into carbohydratesand at least one fourth microorganism capable of convertingcarbohydrates into a preservative organic acid to thereby efficientlyconvert at least a portion of said cellulose into said preservativeorganic acid and prevent accumulation of carbohydrates and therebyinhibition of said conversion of said cellulose into said carbohydrates.2. The process of claim 1, wherein said anaerobic conditions areeffected by packaging the cellulose containing waste within a vacuumtreated airtight bag.
 3. The process of claim 1, wherein said firstinoculum and said second inoculum are added concomitantly to thecellulose containing waste.
 4. The process of claim 1, furthercomprising the addition to said waste of at least one substance suitablefor the nutrition of said first inoculum and said second inoculum. 5.The process of claim 4, wherein said substance is an organic orinorganic substance selected from the group consisting of (NH₄)₂ SO₄,urea, NaCl and animal or poultry manure.
 6. The process of claim 1,wherein said at least one first microorganism is an ediblemicroorganism, said microorganism being a fungus or bacteria of a genusselected from the group consisting of Humicola, Trichoderma andRuminococcus.
 7. The process of claim 6, wherein said at least one firstmicroorganism is selected from the group consisting of Humicola grisea,Trichoderma harzianum and Ruminococcus albus.
 8. The process of claim 1,wherein said at least one second microorganism is a fungus of the genusSaccharomyces.
 9. The process of claim 8, wherein said at least onesecond microorganism is Saccharomyces cerevisiae.
 10. The process ofclaim 1, wherein said at least one third microorganism is an ediblemicroorganism, said microorganism being a bacteria of a genusRuminococcus.
 11. The process of claim 10, wherein said at least onethird microorganism is Ruminococcus albus.
 12. The process of claim 1,wherein said at least one fourth microorganism is an ediblemicroorganism, said microorganism being a bacteria of a genusLactococcus.
 13. The process of claim 12, wherein said at least onefourth microorganism is selected from the group consisting ofLactococcus lactis subsp lactis and Lactococcus lactis subsp cremoris.14. The process of claim 1, wherein said waste is mechanically degradedinto a particulate form.
 15. The process of claim 1, wherein said wasteis moistened by water to 45-65 % of the dry weight of said waste. 16.The process of claim 1, wherein said cellulose containing waste isselected from the group consisting of plant waste, paper waste andanimal manure waste.
 17. The process of claim 1, wherein said aerobicstep prolongs 1-10 days.
 18. The process of claim 1, wherein saidanaerobic step prolongs at least 1 day.
 19. A starting culture forconversion of low protein, cellulose containing, waste into a highprotein fodder or fodder supplement, the starting culture comprising:(a)at least one first microorganism capable of converting cellulose intocarbohydrates under aerobic conditions; (b) at least one secondmicroorganism capable of converting carbohydrates into proteins underaerobic conditions; (c) at least one third microorganism capable ofconverting cellulose into carbohydrates under anaerobic conditions; and(d) at least one fourth microorganism capable of convertingcarbohydrates into a preservative organic acid under anaerobicconditions.
 20. The starting culture of claim 19, wherein said anaerobicconditions are effected by packaging the cellulose containing wastewithin a vacuum treated airtight bag.
 21. The starting culture of claim19, wherein said first inoculum and said second inoculum are addedconcomitantly to the cellulose containing waste.
 22. The startingculture of claim 19, further comprising the addition to said waste of atleast one substance suitable for the nutrition of said first inoculumand said second inoculum.
 23. The starting culture of claim 22, whereinsaid substance is an organic or inorganic substance selected from thegroup consisting of (NH₄)₂ SO₄, urea, NaCl and animal or poultry manure.24. The starting culture of claim 19, wherein said at least one firstmicroorganism is an edible microorganism, said microorganism being afungus or bacteria of a genus selected from the group consisting ofHumicola, Trichoderma and Ruminococcus.
 25. The starting culture ofclaim 24, wherein said at least one first microorganism is selected fromthe group consisting of Humicola grisea, Trichoderma harzianum andRuminococcus albus.
 26. The starting culture of claim 19, wherein saidat least one second microorganism is a fungus of the genusSaccharomyces.
 27. The starting culture of claim 26, wherein said atleast one second microorganism is Saccharomyces cerevisiae.
 28. Thestarting culture of claim 19, wherein said at least one thirdmicroorganism is an edible microorganism, said microorganism being abacteria of a genus Ruminococcus.
 29. The starting culture of claim 28,wherein said at least one third microorganism is Ruminococcus albus. 30.The starting culture of claim 19, wherein said at least one fourthmicroorganism is an edible microorganism, said microorganism being abacteria of a genus Lactococcus.
 31. The starting culture of claim 30,wherein said at least one fourth microorganism is selected from thegroup consisting of Lactococcus lactis subsp lactis and Lactococcuslactis subsp cremoris.